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At least 667 records · Page 37

TomocuPy – efficient GPU-based tomographic reconstruction with asynchronous data processing

Fast 3D data analysis and steering of a tomographic experiment by changing environmental conditions or acquisition parameters require fast, close to real-time, 3D reconstruction of large data volumes. Here a performance-optimized TomocuPy package is presented as a GPU alternative to the commonly used central processing unit (CPU) based TomoPy package for tomographic reconstruction. TomocuPy utilizes modern hardware capabilities to organize a 3D asynchronous reconstruction involving parallel read/write operations with storage drives, CPU–GPU data transfers, and GPU computations. In the asynchronous reconstruction, all the operations are timely overlapped to almost fully hide all data management time. Since most cameras work with less than 16-bit digital output, the memory usage and processing speed are furthermore optimized by using 16-bit floating-point arithmetic. As a result, 3D reconstruction with TomocuPy became 20–30 times faster than its multi-threaded CPU equivalent. Full reconstruction (including read/write operations and methods initialization) of a 2048 3 tomographic volume takes less than 7 s on a single Nvidia Tesla A100 and PCIe 4.0 NVMe SSD, and scales almost linearly increasing the data size. To simplify operation at synchrotron beamlines, TomocuPy provides an easy-to-use command-line interface. Efficacy of the package was demonstrated during a tomographic experiment on gas-hydrate formation in porous samples, where a steering option was implemented as a lens-changing mechanism for zooming to regions of interest.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Convergence and divergence in science and practice of urban and rural forest restoration

Forest restoration has never been higher on policymakers' agendas. Complex and multi-dimensional arrangements across the urban–rural continuum challenge restorationists and require integrative approaches to strengthen environmental protection and increase restoration outcomes. It remains unclear if urban and rural forest restoration are moving towards or away from each other in practice and research, and whether comparing research outcomes can help stakeholders to gain a clearer understanding of the interconnectedness between the two fields. This study aims to identify the challenges and opportunities for enhancing forest restoration in both urban and rural systems by reviewing the scientific evidence, engaging with key stakeholders and using an urban–rural forest restoration framework. Using the Society for Ecological Restoration's International Principles as discussion topics, we highlight aspects of convergence and divergence between the two fields to broaden our understanding of forest restoration and promote integrative management approaches to address future forest conditions. Our findings reveal that urban and rural forest restoration have convergent and divergent aspects. We emphasise the importance of tailoring goals and objectives to specific contexts and the need to design different institutions and incentives based on the social and ecological needs and goals of stakeholders in different regions. Here we discuss the challenges of achieving high levels of ecological restoration and the need to go beyond traditional ecology to plan, implement, monitor, and adaptively manage restored forests. We suggest that rivers and watersheds could serve as a common ground linking rural and urban landscapes and that forest restoration could interact with other environmental protection measures. We note the potential for expanding the creative vision associated with increasing tree-containing environments in cities to generate more diverse and resilient forest restoration outcomes in rural settings. This study underscores the value of integrative management approaches in addressing future forest conditions across the urban–rural continuum. Our framework provides valuable insights for policymakers, researchers, and decision-makers to advance the field of forest restoration and address the challenges of restoration across the urban–rural continuum. The rural–urban interface serves as a convergence point for forest restoration, and both urban and rural fields can benefit from each other's expertise.

54 ENVIRONMENTAL SCIENCES↗

Natural Gas Combined Cycle Carbon Capture Retrofit Database

This tool provides high-level analysis on the incremental costs for retrofitting natural gas combined cycle plants with carbon dioxide capture and/or compression systems. Options are available to include costs of other technological improvements that would be required to comply with various environmental regulations when installing carbon capture technology. This model is based on the NETL report "Cost and Performance of Retrofitting NGCC Units for Carbon Capture" (2023).

03 NATURAL GAS↗

Pulverized Coal CO2 Capture Retrofit Database

This tool provides high-level analysis on the incremental costs for retrofitting pulverized coal plants with carbon dioxide capture and/or compression systems. Options are available to include costs of other technological improvements that would be required to comply with various environmental regulations when installing carbon capture technology. This model is based on the NETL report "Eliminating the Derate of Carbon Capture Retrofits." (2023). For the Excel spreadsheet tools associated with this report, please go to https://www.netl.doe.gov/energy-analysis/details?id=e7e822ff-18ac-4bc6-a052-0be3521b8789

01 COAL, LIGNITE, AND PEAT↗

Plant Cell Biology International Meeting 2022

There is a strong need to develop the knowledge base that will enable the rational design of improved crop species for sustainable agriculture and biomass production. To attain this goal, researchers must learn how plant cells integrate metabolism and cellular dynamics during growth and in response to environmental challenges. Meeting these goals require data sharing and the development and training of faculty, post-doctoral fellows, graduate and undergraduate students in state-of-the-art quantitative integrative cell biology methods. The inaugural Plant Cell Biology International (PCBI) meeting capitalized on the interaction between two well-established plant cell biology communities across the Atlantic, the Midwest Plant Cell Dynamics (PCD) and the European Network for Plant Endomembrane Research (ENPER) and provided a framework to meet these goals. The conference took place in person successfully during August 1-5th 2022 in Crete, Greece. The conference offered opportunities for undergraduate and graduate students, postdocs, young investigators across the globe to present their results and interact across different disciplines. The conference provided an open and inclusive forum for oral presentations that allowed all labs to share research results. It was attended over 80 % by students, postdocs and young investigators. Workshops on best practices for image acquisition and processing pipelines, publication guidelines by scientific journal editors, professional development and well-being benefited the participants at large. Overall, this was the inaugural joint Plant Cell Biology International conference that for the first time officially brought together plant cell biologists to discuss opportunities and challenges in the field to gain a mechanistic understanding of complex biological processes and advance sustainable agriculture. Due to its success, it was rescheduled for 2025 in Crete, to continue strengthening the plant cell biology community and exchanging knowledge and expertise across the globe.

59 BASIC BIOLOGICAL SCIENCES↗

Field Emission Current Transfer for Homopolar Machines

With the increasing electrification of transportation, the need for high power density electric machines is higher than ever. The required specific power for the more demanding applications, such as airplane propulsion, is over 20 kW/kg for multi-megawatt range power levels. Fully superconducting synchronous machines could reach the required performance, but significant challenges remain to be addressed such as AC losses management and rotating cryogenics implementation. Homopolar machines constitute the simplest electro-mechanical conversion systems possible, however the difficulty of establishing reliable and efficient low voltage, high DC current transfer from a stationary to a rotating system has prevented homopolar machines from competing with AC electrical machines. While sliding contacts or liquid metal contacts are feasible, they lead to high losses, high maintenance requirements and the use of environmentally unfriendly materials. We investigated field emission current transfer as an alternative to sliding contacts. We have demonstrated field emission current transfer in vacuum between a copper electrode and carbon nanotubes and diamond pyramids to evaluate the feasibility of contact-free current transfer for homopolar machines. The initial field emission testing was successfully demonstrated with current densities in the 10 mA/cm 2 range. The initial experiments validated the concept and supported the development of a roadmap for the development of contactless current transfer for homopolar machines, helped understand the limitations of the current test system and identify the key parameters that will lead to better performance.

99 GENERAL AND MISCELLANEOUS↗

Fiscal Year 2025 Site Sustainability Plan (Rev. 2)

This document is presented as the Site Sustainability Plan (SSP) for Lawrence Livermore National Laboratory (LLNL), consistent with the instructions provided by the Department of Energy (DOE) received in August 2024 as a deliverable for DOE Order 436.1A Departmental Sustainability requirement. LLNL is certified in Environmental Management System (EMS) (ISO 14001) and aligns sustainability efforts with the EMS.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Hanford Site Revegetation Monitoring Report for Fiscal Year 2025

Revegetation of remediated and disturbed areas on the Hanford Site is performed to support U.S. Department of Energy, Hanford Field Office’s goal of meeting cleanup and revegetation requirements mandated in the Comprehensive Environmental Response, Compensation, and Liability Act of 1980. Revegetation and monitoring activities are conducted in accordance with DOE/RL-2011-116, Hanford Site Revegetation Manual , area-specific revegetation plans, mitigation action plans, and memorandums of agreement.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

The solar electric propulsion stage concept for high energy missions.

Definition of multimission and engine performance requirements for candidate solar electric propulsion stage configurations, considering launch vehicle compatibility, electric propulsion integration, payload requirements, and the effects of environmental extremes. Electric propulsion power options include two solar array power levels (15/22 kW), up to twelve electric thrustors of 30 cm diameter and 2.7 kW each, five to eight power conditioning units, and a maximum mercury propellant capacity of 1530 kg. In performance, the stage with a dry weight of 700 to 900 kg can deliver a net mass of 756 kg into Saturn orbit, 329 kg into a tight Mercury orbit, and 334 kg within 0.1 AU of the sun. The stage can also deliver a round trip payload of 3350 kg to geosynchronous orbit and return from an intermediate elliptical orbit using the Shuttle/Tug. Thus, a versatile stage is developed which competes effectively in performance with existing integrated spacecraft and promises considerable savings in total program costs.

Guttman, C. H.↗

An operational application of ERTS-1 imagery to the environmental inventory process

A discussion is presented of how The Engineer Agency for Resources Inventories utilized ERTS remotely sensed imagery as a/supplement to airphotos and collateral data for an environmental impact study of the Atchafalaya Basin for the New Orleans engineer district. This single overall inventory permitted a systematic approach and substantial economy for a number of engineering projects for which environmental impact statements would be required. The study area covered approximately 25,000 square miles and included all or part of 36 parishes in Louisiana and 8 counties in Mississippi. It was concluded that as a supplementary source, used in conjunction with airphotos, ERTS had proven itself as a significant means of economy. As a primary source, the Engineer Agency is not yet ready to accept ERTS for their own particular applications.

Oneal, J. D.↗

Apollo command and service module and lunar module environmental control systems

The environmental control systems and system requirements of the Apollo command service module and the lunar module are described. The overall performance of both systems during the Apollo program is discussed. Other topics covered include: dust control, EVA provisions, Apollo 13 emergency, component redundancy, modular construction, and subatmospheric design.

James C. Brady↗

Energy Conversion Alternatives Study (ECAS)

ECAS compared various advanced energy conversion systems that can use coal or coal-derived fuels for baseload electric power generation. It was conducted in two phases. Phase 1 consisted of parametric studies. From these results, 11 concepts were selected for further study in Phase 2. For each of the Phase 2 systems and a common set of ground rules, performance, cost, environmental intrusion, and natural resource requirements were estimated. In addition, the contractors defined the state of the associated technology, identified the advances required, prepared preliminary research and development plans, and assessed other factors that would affect the implementation of each type of powerplant. The systems studied in Phase 2 include steam systems with atmospheric- and pressurized-fluidized-bed boilers; combined cycle gas turbine/steam systems with integrated gasifiers or fired by a semiclean, coal derived fuel; a potassium/steam system with a pressurized-fluidized-bed boiler; a closed-cycle gas turbine/organic system with a high-temperature, atmospheric-fluidized-bed furnace; a direct-coal-fired, open- cycle magnetohydrodynamic/steam system; and a molten-carbonate fuel cell/steam system with an integrated gasifier. The sensitivity of the results to changes in the ground rules and the impact of uncertainties in capital cost estimates were also examined.

Source record↗

Energy Conservation Alternatives Study (ECAS): Conceptual Design and Implementation Assessment of a Utility Steam Plant with Conventional Furnace and Wet Lime Stack Gas Scrubbers

A study was performed to estimate the technical/economic characteristics of a steam power plant (3500 pounds per square inch gauge, 1000 degrees Fahrenheit / 1000 degrees Fahrenheit) with a coal-burning radiant furnace and a wet lime stack gas scrubber to control sulfur emissions. Particulate emissions were controlled by an electrostatic precipitator operating at 300 degrees Fahrenheit. The stack gas from the scrubber was reheated from 125 degrees Fahrenheit to 250 degrees Fahrenheit as a base case, and from 125 degrees Fahrenheit to 175 degrees Fahrenheit as an alternate case. The study was performed on a basis consistent with the General Electric ECAS Phase II evaluation of advanced energy conversion systems for electric utility baseload applications using coal or coal-derived fuels. A conceptual design of the power plant was developed, including the on-site calcination of limestone to lime and the provision of sludge ponds to store the products of flue gas scrubbing. From this design, estimates were derived for power plant efficiency, capital cost, environmental intrusion characteristics, natural resource requirements, and cost of electricity at an assumed capacity factor of 65 percent. An implementation assessment was performed where factors affecting applicability of the conceptual design power plant in electric utility generation systems were appraised. At 250 degrees Fahrenheit and 175 degrees Fahrenheit stack gas temperatures respectively, the plants showed a cost of electricity of 39.8 and 37.0 mills per kilowatt-hours and overall plant efficiencies of 32 percent and 34 percent.

Brown, Dale H.↗

Environmental observations from space present and future

Spaceborne systems for measuring and predicting environmental conditions have achieved a level of development that justifies a look at the total environmental system. There are common requirements in all the disciplines, and many of the same measurements are needed to satisfy various discipline needs. It is this factor - the commonality of needs and measurements - that will be used in our future missions. The needs and requirements in the future plan will be faced by combining mission and data requirements that may be satisfied from orbiting spacecraft. There are also similarities in information requirements, as a result of which there is a need for developing an integrated data/information system where information will be produced in a format that will be of immediate utility to the users.

Greenwood, L. R.↗

Automatic Calibration Systems

A continuous requirement exists for calibration and environmental testing of instruments in use at multitude of test facilities at Langley Research Center. Brief summarizes several automated systems available for calibration of research instruments to include: six-component balance, multimeter, amplifier, pyrometer, voltage-controlled oscillator, pressure transducer and accelerometer.

Ferris, A. T.↗

Back-Pressure Regulator for Large Gas Flows

Cost reduced, and safety enhanced. Pipe exit partially obstructed by conical throat plug. When pressure in pipe falls below (or rises above) desired back pressure, plug automatically moved in (or out). Applications of system lie in environmental testing or production facilities requiring large gas flows at low pressures.

Theodore, E. A.↗

Manned Mars mission environmental control and life support subsystem

A specific design is not presented, but the general philosophy regarding potential Environmental Control/Life Support System (ECLSS) requirements, concepts, issues, and technology needs are discussed. The focus is on a manned Mars mission occurring in the late 1990's. Discussions on the Trans-Mars Vehicle, the Mars Excursion Module (MEM), and a Martian base facility are covered. The functions, performance requirements, and design loads of a typical ECLSS are listed, and the issues and technology briefly discussed. Several ECLSS concepts and options are identified, and comparative weights and volumes are provided for these. Several aspects of the space station ECLSS are contrasted with the Mars element ECLSS.

Hueter, Uwe↗

Corrosion fatigue crack propagation in metals

This review assesses fracture mechanics data and mechanistic models for corrosion fatigue crack propagation in structural alloys exposed to ambient temperature gases and electrolytes. Extensive stress intensity-crack growth rate data exist for ferrous, aluminum and nickel based alloys in a variety of environments. Interactive variables (viz., stress intensity range, mean stress, alloy composition and microstructure, loading frequency, temperature, gas pressure and electrode potential) strongly affect crack growth kinetics and complicate fatigue control. Mechanistic models to predict crack growth rates were formulated by coupling crack tip mechanics with occluded crack chemistry, and from both the hydrogen embrittlement and anodic dissolution/film rupture perspectives. Research is required to better define: (1) environmental effects near threshold and on crack closure; (2) damage tolerant life prediction codes and the validity of similitude; (3) the behavior of microcrack; (4) probes and improved models of crack tip damage; and (5) the cracking performance of advanced alloys and composites.

Gangloff, Richard P.↗